Waste wash water and waste binder reuse system and apparatus for mineral fiber forming process



Dec. 5, 1967 Q A, SMUCKER ET AL 3,356,565

WASTE WASH WATER AND WASTE BINDER REUSE vSYSTEM AND APPARATUS FOR MINERAL FIBER FORMING PROCESS Filed Aug. 13, 1964 2 Sheets-Sheet l De.5,1967' I C A,SMUCKER ETAL 3,356,555

WASTE WASH WATER AND WASTAv BINDER REUSE SYSTEM AND APPARATUS FOR MINERAL FIBER FORMING PROCESS Filed Aug. 13, 1964 2 Sheets-Sheet .6U/WON M PAL MEA INVENTORS United States Patent O 3,356,565 WASTE WASH WATER AND WASTE BWDER REUSE. SYSTEM AND APPARATUS FOR li/HNERAL FIBER FGRMlNG PROCESS Clayton A. Smucker and William H. Rigby, Jr., Newark, and Philip H. Klein, Jr. and Burton M. Palmer, Toledo, (Ehio, assignors to Gwens-Corning Fiberglas Corporation, a corporation of Delaware Filed Aug. 13, 1964, Ser. No. 389,337 S Claims. (Cl. 162-199) This invention relates to a waste wash water and waste binder reuse system and apparatus for use with liber-forming apparatus and particularly to a wash water recirculating system for the use with methods and apparatus of forming heat-softened mineral materials to fibers wherein a binder composition is delivered onto the attenuated iibers and the binder treated fibers collected upon a moving foraminous surface.

The method and apparatus involves circulating wash water in a closed fluid circuit for purging the fiber collecting surface of excess binder and recirculating the excess binder for re-application to the fibers. The invention comprehends a method of control of constituents of the binder composition and the `delivery of the binder composition to one or more ber-forming stations.

It -has been conventional practice in the formation of glass bers or fibers of other mineral materials to deliver a binder containing resin and other ingredients onto the fibers which are formed by attenuation through the use of high velocity attenuatin-g blasts and the bers treated with binder collected in a mass upon a moving foraminous conveyor and establishing a reduced pressure zone beneath the fiber collecting region to convey away the spent gases of the attenuating blasts and to assist in the deposition of the `fibers on the conveyor and convey away waste binder filtering through the fibrous mass and the foraminous conveyor. It has also been a practice to direct jets or pressure streams of water onto the moving conveyor in an endeavor to effect same cleaning of the conveyor to remove binder adhered thereto, the water carrying whatever binder is rdislodged from the conveyor being disposed of as waste. In such methods, substantial quantities of excess binder are lost and all of the spent wash water is wasted.

In such methods it becomes necessary to periodically interrupt the liber-forming operation in order to manually clean the foramious conveyor to remove binder which adheres to the conveyor, which, if permitted to accumulate on the conveyor, reduces or impairs the eilectiveness of the reduced pressure or suction for disposing the spent lgases of the ber attenuating blasts. In systems of this character, tremendous amounts of water are disposed of as waste.

The present invention embraces the provision of a method or system of recirculating for reuse, wash water utilized in cleaning a foraminous conveyor in a manner effective to continuously remove binder adhered to the conveyor, and feeding an akaline detergent into the wash water to provide more effective washing or cleaning of the conveyor in conjunction with the preparation of binder composed of several ingredients wherein the wash water bearing the detergent is reused in preparing batches of binder mix and treated in a manner to reduce the alkalinity by effecting a reaction in the binder mixing stage to form insoluble matter which is compatible in the binder mix in order to enable the recirculation and reuse of the alkaline w-ash water employed in cleaning the conveyor.

Another object of the invention resides in a closed water recirculating wash system for a conveyor and a binder mix system wherein the otherwise waste binder which lters through the fibers and the foraminous conveyor and ice the binder pur-ged from the conveyor by the wash water is recovered and the wash water containing the excess or waste binder treated with a caustic or alkaline detergent and the treated wash water continuously filtered to remove insoluble matter whereby water containing the detergent is recirculated for continuously cleaning the conveyor and a portion of the Water reused in the binder mix system as a binder ingredient vehicle for conveying the binder onto attenuated fibers prior to their collection on the conveyor and wherein an ingredient is introduced at the binder mixing stage to effect, by reaction with the alkaline detergent, an insoluble material which is compatible in the binder mix and reduce the alkalinity of the wash water employed for binder mix batches.

Another object of the invention resides in a method wherein a batch of binder is periodically mixed and conveyed to a binder delivery system to prevent the use of stale binder, the method being continuous in that the individual batches of binder are automatically and periodically mixed without appreciable loss of wash water except the water adhering to the collected bers, the method involving the continuous addition of fresh water into the closed circulating system to replenish the water loss.

Another object of the invention resides in the provision of a closed wash water recirculating system for Washing a fiber collecting conveyor to remove binder adhering to the conveyor in which an alkaline detergent is added in conjunction with a binder batch mix system wherein wash water of the closed system is delivered to a batch mixing tank in which is introduced an acid constituent to neutralize the high alkalinity of the wash water to render it compatible with the ingredients of the binder composition.

Another object of the invention resides in the provision of a closed wash water circuit for cleaning a foraminous fiber collecting surface at a ber forming station in conjunction with a binder forming and delivery system which includes feeding a detergent hydroxide into the wash water circuit to promote improved cleaning of the conveyor and circulating a portion of the Iwatcr containing the detergent hydroxide to a binder mixing tank and introducing a material which reacts with the detergent hydroxide to form an insoluble salt which is inert in the binder composition and inert in the mass of bers collected on the conveyor, the formation of the insoluble precipitates reducing the alkalinity of the water in the binder mix tank whereby the binder ingredients are compatible with and may be mixed together in the wash water facilitating continuous reuse of the water.

Another object of the invention resides in a binder system for delivering binder onto newly formed mineral fibers such as glass fibers at a plurality of fiber-forming stations involving control of the delivery of the binder individually to each ber-forming station whereby the delivery rate of binder at the respective stations may be varied and controlled automatically to vary the amount of binder in various regions of the mass of fibers collected from several fiber-forming stations.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

FIGURE l is a schematic view illustrating a plurality of fiber-forming stations in association with a closed wash water recirculating and binder reuse system of the invention, and

FIGURE 2 is a schematic view of an arrangement for sensing and controlling delivery of binder to a fiber-forming station.

While the invention embraces a wash water and waste binder reuse system having particular utility with one or more fiber-forming stations at which blast attenuated fibers are formed of glass or other mineral material wherein binder is delivered onto the fibers and the bers collected in a mass on a moving foraminous conveyor or collector, it is to be understood that the method, system and arrangement of the invention may be used wherever the same may be found to have utility.

Referring to FIGURE 1 illustrating schematically the components and their association for carrying out the method or system of the invention, a plurality of fiberforming units or fiber-forming stations are illustrated which are of the so-called rotary type, but it is to be understood that other fiber-attenuating methods and apparatus may be employed and that one or more fiberforming stations may be utilized. Each of the fiber-forming units 10 is of conventional rotary character wherein a revoluble rotor, rotated at comparatively high speed by a motor (not shown), has a peripheral wall provided with a large number of small openings.

Heat-softened fiber-forming mineral material, such as heat-softened glass, from a supply (not shown) is delivered into the rotor and, under the iniiuence of centrifugal forces of rotation the softened material is projected through the openings in the rotor wall as primary filaments.

The projected primary filaments are engaged by an annularly-shaped downwardly-directed high velocity gaseous blast which attenuates the material of the filaments to fibers 14. Such fiber-forming apparatus may be of the character shown in U.S. Patent 2,949,631.

The attenuated fibers and attenuating gases move downwardly through a generally rectangular fiber-forming chamber 16 provided by a hood or casing 18, the forward end being removed for purposes of illustration, the side Walls 19 preferably being divergent `as shown. Disposed beneath the fiber-forming station or stations is a fiber collecting means which, in the embodiment illustrated, is an endless conveyor 20 of reticulated or foraminous character supported upon rolls 22.

The upper flight 24 of the foraminous conveyor, moving generally `horizontally through the base region of the fiber-forming hood 18, provides a fiber-collecting surface on which the fibers from the one or more fiber-forming stations are accumulated in a mass 26 0f haphazardly arranged fibers. An uncured binder composition, of a character hereinafter described, is delivered to each fiberforming station by an applicator or nozzle arrangement 28 onto the newly formed fibers, preferably before they are deposited on the conveyor flight 24.

The binder applicator may be in the form of an annular ring surrounding the beam of fibers moving downwardly from the `fiber-forming unit, the ring being provided with binder delivery nozzles of conventional character.

One of the conveyor supporting rolls 22 is driven by motive means (not shown) in a conventional manner for advancing the upper fiight 24 in the direction of the arrow at a desired speed depending upon the `thickness of the mass of fibers to be continuously collected on the conveyor.

Positioned beneath the upper flight 24 of the conveyor is a rectangularly-shaped hollow member 30 which defines a suction chamber or region of subatmospheric pressure, the upper open area of the chamber being arranged at the fiber collection region of the flight 24 of the conveyor. The member 30 is connected with a suction blower 32 by means including a tube or pipe 34 connected with a hollow member 36 which denes an air washing chamber 38, the latter being connected with a hollow member 40 containing filter media, the filter chamber 40 being connected to the exhaust or suction blower 32 by a pipe 42. The purpose and function of the air washing chamber 38 will be hereinafter explained.

rIhe invention is inclusive of a closed circuit or wash water reuse or recirculation system for cleaning the conveyor 20, for recovering or reclaiming waste or excess binder, and for utilizing treated wash water as a constituent or vehicle of the binder composition for application to the fibers. As the fibers collected on the conveyor flight 24 are coated with an uncured binder composition, which is tacky or adhesive in nature, some binder filters through the mass of fibers and tends to adhere to or build up or accumulate upon the foraminous conveyor.

By reason of the subatmospheric pressure or suction effective in the chamber provided by the member 30, which conveys away spent gases of the blasts and induced air entering the hood |18, some unused binder passes through the conveyor fiight 24 and is entrained in the air stream moving through the tube 34. Disposed beneath the conveyor 20 is a drain pan, tank or receptacle 46 equipped with a drain tube 4S which, in the embodiment illustrated, is connected with a wash water treating charnber or sump 50. The air washing chamber 3S is also connected with the sump 5() by a pipe 52.

The wash water chamber 38, the drain pan or receptacle 46, and the sump 5@ are components of a closed wash water recirculating system. A water line or pipe 54 is connected with a fresh water supply. The supply line 54 is connected by a pipe 53 with a receptacle or tank 6i) defining a chamber 62 for heat-conditioning the wash water and fresh water which is added from the fresh water supply to replenish water or moisture loss through the exhaust blower 32 and water adhering to the fibers derived from the water in the binder composition.

The tank 60 is provided with a heating element 64 preferably of the electrically energizable type equipped with a conventional thermal control (not shown) for maintaining the temperature of the wash water in the tank 60 within a desired range. The purpose of heating the wash water in the chamber 62 is that improved cleaning of the conveyor 24 is attained by using heated water.

Disposed in the chamber 62 is a conventional float controlled valve mechanism 66 connected `with the fresh water inlet 58 so as to automatically admit fresh water from the fresh water supply into the wash water circulating system to maintain constant the amount of water in the closed system.

Disposed above the chamber 62 is a vibrating screen, lter` or separator 68 of conventional construction for separating solids. or insoluble matter from the wash water, the insoluble matter separated from the wash water being delivered into a waste receptacle 69 through a tube 70. The heated Water in the chamber 62 flows to a pump 72 through a pipe 73, the outlet pipe 74 of thetpump being connected with pipes 76 and '78.

The pipe 76 is connected by `a pipe S0 with a high pres-r sure pump 82, the outlet pipe 84 of the pump being connected with delivery nozzles 86 for projecting wash water under high pressure at high velocity against the conveyor 20. Journally supported so as to engage the outer surface of the conveyor 20 is a rotatable brush 90` rotated by a suitable means (not shown) to assist in loosening and removing binder adhering to the conveyor 20, the sprays or jets of wash water from the nozzles 86 cleansing or removing binder from the conveyor and the rotatable brush and the spent wash water containing the waste binder being collected in the pan 46 and drained into the sump or collector 50.

The method of the invention includes an arrangement for feeding a caustic or alkaline detergent into the wash water to thereby greatly improve the cleaning of binder from the conveyor. In the embodiment illustrated, a tank or receptacle 94 is disposed'near the sump 50 and is adapted to contain a supply of alkaline detergent such as barium hydroxide. The tank 94 is connected by a pipe 95 with a member 96 enclosing a controlled detergent feeding means such `as a rotatable screw 97 driven by a motor 98. By controlling the operation of the motor 98, the delivery of detergent from the tank 94 into the sump 5G may be regulated.

The cleaning efficiency of the wash water is dependent in a large measure upon the amount of alkaline detergent in the water wash system and the degree of alkalinity of the wash water in the sump 5t) may be utilized for controlling the feeding of detergent into the sump. For this purpose the sump 5t) is provided with an alkalinity sensor 100 of conventional construction connected with a switch means or relay 102 connected in the circuit of the motor 98 and arranged to control an energizing circuit to the motor to maintain the alkalinity of the wash water within :a predetermined range.

It is found desirable for satisfactory washing efficiency of the conveyor to maintain the pH factor of the wash water preferably above 8.0. By this method the wash water delivered into the sump 50 is treated with detergent before it is reused or recirculated for cleaning the conveyor.

The wash water from the sump S0 flows through a pipe 106 to a low pressure pump 108, the outlet pipe 110 of the pump terminating at a region to deliver the wash water and ingredients entrained therein into the separator or screen arrangement 68.

Thus, a closed water Wash circuit or loop is provided for continuously impinging detergent-bearing wash Water against the conveyor by means of the jets 86, the spent wash water containing the waste binder flowing from the pan 46 into the sump 50.

The pipe 78 delivers sprays of wash water into the chamber 38 for removing stray fibers and waste binder that may be drawn through the collected fibers 26 and through the openings in the conveyor 20 under the infinence of reduced pressure or suction existent in the suction chamber 30. The stray fibers and waste binder separated from the air streams in the chamber 38 flow through the pipe 52 into the sump 59.

As waste binder is being continuously removed from the conveyor 20 and from the air Washing chamber 38, the method or system embodies an arrangement for taking some water out of the wash water loop circuit as otherwise the wash water would soon contain an excess accumulation of waste binder. ln the method of the invention, water is removed from the system in several ways viz. (l) water retained in the mass of collected fibers derived from the Water in the binder, (2) moisture drawn away by the suction blower 32, and (3) by evaporation.

In order to continuously promote the removal from the system of some of the wash water containing binder and to effect reuse of the waste binder, a portion of the wash water is diverted or conveyed to the binder system and the diverted wash water treated to render it compatible with the binder ingredients. The binder mixing and delivery phase of the wash water reuse system or circuit includes a pipe 114 connected with the pipe 76, the pipe 114 `being connected with a filter 116 for the purpose of filtering or straining insoluble solids such as fibers which may have filtered through the conveyor flight 24 and m-ay not have been removed by the separator or screen 68.

A tank 118 for cooling or thermally conditioning wash water for the binder mix is arranged to receive the detergent-treated wash water through a pipe 120 connected with the filter 116i. Wash water is continuously being supplied to the conditioning tank 118 by the pump 72 disposed to receive heated wash water from the chamber 62. The tank 118 is provided with an overliow pipe 122 providing a constant level of wash water in the tank 118 and returns the excess water into the drain pan or tank 46.

Disposed in the tank 118 is a heat transfer means or cooling coil 124 which may be connected with a separate supply of water for circulation through the coil -124 to 6 thermally condition or cool the wash water in the tank 118.

It is desirable to maintain the temperature of the wash water in the tank 118 at a lower temperature than the temperature of the heated water from the chamber 62 in order to prevent precuring of ingredients in the binder mix. A stirring device or agitator 126 is disposed in the tank 118 driven by a motor 128 to agitate the Wash water in the tank so as to promote the maintenance of uniform temperature. l

The binder system is inclusive of a Ibinder batch mixing station which includes a tank or receptacle 130, the tank 130 receiving water from the tank 118 through a pipe 132 connected with a pump 134 and the pump connected with the tank 118 by a pipe 136. The motive means driving the pump 134 is electrically controlled by conventional programming means (not shown) to periodically deliver water into the mixing tank 130 at each period of mixing a -batch of binder in the tank 130.

The binder system utilizing recirculated wash water for periodically mixing individual batches of binder includes means for conveying each individual batch mix to a binder circulating station or feed tank for delivery onto the fibers immediately after mixing so that the binder does not become stale. The binder mix includes at least one ingredient which is introduced into the mixing tank 130 with other ingredients which reacts with the barium hydroxide in the wash water in the mixing tank to reduce the alkalinity of the wash water in the mixing tank to render it compatible with the other ingredients of the binder mix and to form an insoluble compound or precipit-ate which is inert in the binder mix and which is delivered onto the fibers with the binder.

The inert material in the mass of fibers does not affect the insulating characteristics or other properties of the mass of fi-bers and the production of this inert material in the system enables the automatic recirculation and reuse of waste binder from the sump 50` in subsequent batches in a manner to render binder application and conveyor washing operations continuous without the accumulation of otherwise waste binder in the wash water system. The binder mix includes, but is not limited to, ingredients such as ammonium sulphate, ammonia, resin and oil.

Insoluble material delivered onto the fibers which may pass through the mass of bers on the conveyor flight 24 and any stray fibers dislodged from the conveyor are delivered into the sump 50 and are pumped to the shaker screen or separator 68 which filters out fibers and insoluble inert particles from the water circulating system.

Disposed within the binder mixing tank 130 is an agitator or stirrer driven by a motor 141, the operation of the motor being controlled by the programming means (not shown) which actuates the motor driving the water feed pump 134. The binder system includes a plurality of containers or tanks 142, each adapted to contain an ingredient or composition of ingredients for eventual delivery into the binder mix tank 130 in the preparation of each batch binder.

Some of the binder ingredients or composition of ingredients are mixed with fresh water supplied from an extension 55 of the fresh water supply line 54 connected with the tanks 142 wherein water is supplied to the ingredient or composition of ingredients in one or more of the tanks 142 prior to delivery therefrom of material from the various tanks into the binder mixing tank 130. One of the tanks 142 contains ammonium sulphate.

The flow lines 144 from the tanks 142 are arranged to deliver the binder ingredients into the mixing tank 130 and valves (not shown) are associated with the flow lines 144 controlled automatically by the batch control programming means (not shown) for effecting delivery of the binder ingredients or compositions of ingredients in a desired order or sequence and in the desired amounts to prepare the binder mix in the tank 130. The initial step in preparing the binder mix is the actuation of the pump 7. 134 to effect delivery into the mixing tank 130 of the highly alkaline water wash which has been pretreated with alkaline detergent, barium hydroxide fed into the sump 50.

Upon filling of the binder mix tank 130 with the highly alkaline wash water, the motor 141 is energized to rotate the agitator 140, and the ammonium sulphate and other` binder ingredients are introduced into the water in the mixing tank 130 in the proper amounts by conventional valve means (not shown) controlled by conventional programming means.

The rotating agitator 140 thoroughly mixes the ingredients. The presence of the ammonium sulphate in the mixing tank 130 reacts with the barium hydroxide in the wash water to result in the formation of barium sulphate, and ammonia.

The barium sulphate is an insoluble salt or precipitate and is inert in the binder mix. The insoluble barium sulphate reduces the alkalinity of the wash water in the mixing tank to an extent to render it compatible with the other ingredients of the binder mix. Disposed to receive binder batch mix in the mixing tank 138 are tanks 148 and 150, one of the tanks being used as a standby to facilitate the use of modified binder mix without interfering with the companion tank 156. Thus in normal operation the tank 148 receives `the successive batches of binder mix and the mix delivered therefrom onto the fibers at the fiber-forming stations.

A pipe 152 arranged to convey batch mix from tank 130 into the tank 148 is provided with an automatically controlled valve 154. The valve 154 is controlled through a probe device (not shown) of conventional construction disposed in the tank 148 and connected with the programming control. When the supply of binder mix in a tank 148 is lowered to a level below the probe, the valve 154 is actuated to permit flow of the binder mix from the tank 130 into the feed or circulating tank 148.

A pipe 156, connected with the lower end of the tank 148, `conveys the mix to a pump 158 which is continuously driven by suitable motive means (not shown) for conveying the binder mix from tank 148 to the several fiberforming stations. Connected with the outlet of the pump 158 is a binder supply manifold or pipe 160 which supplies binder to individual binder flow control mechanisms 162 arranged adjacent each fiber-forming station, one of the control mechanisms 162 being schematically illustrated in FIGURE 2. The binder from each control mechanism is deliveredthrough a pipe 164 to an applicator 28 for delivery onto the newly formed fibers.

The manifold 60 feeds binder to all of the control devices 162 and is connected with a return line or pipe 168 to return any excess binder into the tank 148 past a valve 170 which is normally opened during use of the tank 148. The standby tank 150 is connected with the binder mix tank 130 by a pipe 152' provided with a valve 154', the valve 154' being normally closed during the use of the tank 148.

The standby tank 150 is connected by a pipe 156 to the inlet of the pump S. interconnected in the pipe 156 is a valve 157 which is normally open when the tank 148 is in use. A similar valve 157 is interconnected with the pipe 156 but it is normally closed when the standby tank 150 is not in use. By maintaining valves 154, 157 and 170 closed and programming the opening of the valves 154', 157 and 170', the binder mix may be diverted into the tank 150 and the tank 14S taken out of service for purposes of cleaning or as a standby tank.

A `control device 162, schematically shown in FIG- URE 2, is provided for each of the binder applicators 28. Disposed between the manifold 160 and a flow sensing means 174 of a flow control 162 is a manually operated valve 176 to interrupt flow of binder to a fiber-forming station in the event the fiber-forming station is taken out of service. The flow sensor 174 is of conventional construction and includes a binder flow responsivemeans arranged to actuate an adjustable controller 178 which,

in turn, is adapted, by pneumatic means to automatically adjust the position of a control valve 180 in the binder discharge pipe or line 164 for conveying binder to the adjacentapplicator 28 at a fiber-forming station.

The controller 178, individual to each binder applicator, may be adjusted to modify or change the amount of binder per unit of time delivered onto the fibers at a particular station. By this method, the amount of binder may be varied in different portions of the mass of fibers collected upon the conveyor flight 24. By way of example, where several fiberforming stations are arranged to deliver fibers to form an accumulating mass, a small volume of binder may be delivered onto the fibers from the first fiber-forming station so that the collected fibers contiguous to the conveyor flight 24 contain or are treated with a comparatively small amount of binder.

The fibers from the succeeding stations may be treated or coated with a greater volume of binder so that the region or zone of the mass adjacent the fibers first deposited on the conveyor flight are provided with a greater amount of binder. The volume of binder delivered onto the fibers at any of the fiber stations may thus be automatically regulated or controlled so that a fibrous mat formed from the mass of collected fibers from the several stations will be endowed with different amounts of binder in different zones or regions of the mat.

Theaccumulated mass of binder-bearing fibers 26 on therconveyor fiight 24 may be compressed by a sizing roller (not shown) of conventional construction arranged at the exit end of the fiber-forming hood 18 to compre-ss the fibers to a mat of predetermined thickness. The fibrous mat is then conveyed through a curing zone or oven to cure or set the binder to establish mass integrity in the fibers of the mat.

rlhe closed or recirculating wash water circuit for continuously cleaning and removing binder adhering to the forarninous conveyor 20 and for mixing successive batches of binder utilizing wash water of the recirculating washing circuit, and the arrangement for supplying binder to the fibers produced at one or more fiber-forming stations function in the following manner: The conveyor 20 is continuously driven at a speed at which it is desired to produce `a fibrous mat of desired thickness and density.

For example, by advancing the conveyor at a comparatively low speed, the amount of fibers accumulating on the conveyor flight 24 in a given length of the conveyor is increased providing a thicker mass of fibers. If the conveyor speed is increased, while maintaining the same rate of fiber production, a fibrous mass of lesser thickness is produced. The suction blower 32 and the brush 90, engaging the conveyor 20, are operated continuously. The pumps 72 and 108 operate continuously but are of the low pressure type developing about 20 p.s.i.

The pump 82 is operated continuously but is of a character to develop comparatively high pressure of about 300 p.s.i. for the wash water in the line or pipe 84 whereby the wash water is projected from the nozzles 86 onto the conveyor 20 and the rotating brush 90 at high velocity and substantial force to effectively remove tacky `binder adhering to the conveyor 29. The pump 72 continuously recirculates wash water to the air wash chamber 38 for washing the air and spent attenuating gases removed from the suction chamber 30 by the suction blower 32, the wash water in the chamber 38 removing the major amount of entrained binder which may pass downwardly through the conveyor flight 24.

The waste binder removed from the conveyor Ztl and the wash water delivered from the nozzles 86 collects in the pan 46 and, together with the spent wash Water in the chamber 38, drains into the sump 50.

The alkaline detergent, barium hydroxide, contained in the tank 94 is delivered into the sump 50 through the motor operated feeder 96, the feeder being controlled by the alkalinity sensor to continuously maintain a 9 proper amount of alkaline detergent in the wash water in the sump 50.

The highly alkaline wash water 'is delivered by the pump 1x08 into the mechanical shaker screen or separator 68, which filters `out or removes insoluble particles and stray fibers that may have passed through the openings in the conveyor. The screen or separator 68 is arranged to deliver the insoluble matter or stray fibers into a waste receptacle 69. As water is continuously being removed from the wash water circuit as water in the binder adheres to the fibers and water is exhausted into the atmosphere `by the blower 32, it is necessary to continuously add fresh water from the fresh Water supply line 54 into the closed wash water circuit.

The automatic control mechanism 66, regulates the amount of fresh water from fresh water line 58 to maintain, at all times, ya predetermined level of water in the chamber 62 provided by the tank 60 so that the same amount or volume of water is maintained in the wash water circuit at all times.

The heater 64 is energized to raise the temperature of the water in the chamber 62 whereby the heated wash water in chamber 62 is conveyed by the pumps '72 and 82 `for delivery from the jets or nozzles 86 onto the conveyor at the region of the rotating brush 99 to more effectively clean the conveyor. The use of heated water having a controlled amount of alkaline detergent in conjunction with the cleaning brush 90 removes waste binder adhering to the foraminous conveyor 20.

This cleaning action is continuous and the wash wate-r containing the waste `binder collected in the pan 46 together with the wash water moving through the chamber 38, is continuously drained into the sump 50 and therein treated with additional alkaline detergent, such as barium hydroxide, to perpetuate the cleaning effectiveness of the wash water.

The `binder mixing and binder delivery phase of the closed wash water circuit is as follows: Assuming that a biatch of binder mix in the feed tank 148 is substantially exhausted through the binder delivery pump 158 until the level of the mix in the binder Ain the feed tank 148 is reduced below the sensing probe in the tank 148, the conventional programming control initiates delivery of a mixed batch of binder in the mixing tank 130 into the tank 148 by automatic operation of the valve 154.

The actions and operations during preparation of a succeeding batch of binder are as follows: When the batch mix from the tank 130 has been delivered through the' pipe 1512 into the tank 148, the programming control closes the valve 154 and energizes t-he motor for driving the pump 134 to deliver the highly alkaline wash water from the temperature-conditioning or cooling chamber' 118 into the binder mix-ing tank 1313, and the motor 141 energized to actuate the agitator 146. The wash water is delivered lcontinuously by the low pressure pump 72 into the wash water conditioning tank 11S through the pipe 120, the level of the wash water in the tank 118 being determined b'y the position of the overflow pipe 122, the excess wash water flowing through the overflow pipe 122 into the pan 46 and returned to the sump 50.

The wash water in the conditioning tank 118 is continuously agitated by the agitator 126 to assure uniform cooling or temperature conditioning of the wash water in the tank 118. Upon the closing of the valve 154 adjacent the tank 148., the pump 134 is automaticaly energized to pump the highly alkaline wash water from the tank 118 into the mixing tank 130 to a level controlled by a probe means (not shown) in a conventional manner.

Fill valves (not shown) connected with the tanks 142 are opened and the components or ingredients or mixtures of ingredients from supplies are delivered into the tanks 142 and when the required quantities of ingredients or mixtures of ingredients are delivered into the tanks 142, the fill valves are closed automatically.

Valves (not shown) are intercalated in the pipes 144 10 leading from the tanks 142 into the mixing tank 131i, which are automatically controlled by conventional programming means to provide for the delivery of the binder ingredients from the tanks 142 into the mixing tank 130 in a desired sequence.

The ingredients include but are not restricted to ammonium sulphate and ammonia, resin and oil, and the agitator or stirring device 146 thoroughly mixes the binder ingredients into a homogeneous batch.

The presence in the batch mixin-g tank of ammonium sulphate and barium hydroxide in the wash Water effects a reaction resulting in the formation of barium sulphate and ammonia. The barium sulphate is precipitated as an Vinsoluble salt in fine particle form. This reaction with the alkaline detergent, barium hydroxide, reduces the alkalinity of the wash Water in the binder mix to render the wash water compatible with the several ingredients in the binder mix. The alkalinity may be reduced to a point approaching a neutral or pH factor of 7.

It has been found that the addition of the alkaline detergent in the sump 58 to an alkaline pl-I of between 8.2 and 8.5 is satisfactory for cleaning the conveyor 20 and, in the binder mix tank, the reaction with ammonium sulphate materially reduces the alkalinity whereby the slightly alkaline wash water is compatible with the ingredients of the binder mix.

The barium sulphate, being insoluble, is carried along with the binder delivered onto the fibers and becomes an inert ingredient in the mass of collected fibers.

Any insoluble particles of barium sulphate passing through the -collected mass of fibers and the foraminous conveyor are merely recirculated in the closed wash water circuit or are removed as waste by the filter or separator mechanism 68. The pump 158 is continuously operated to convey the binder through the supply line or manifold 16d lto each of the control mechanisms 162, illustrated in FIGURE 2, adjacent the fiber-forming stations, the Vline 168 providing for the return into the feed tank 148 of the binder oversupply provided by the pump 158.

Each control unit 162 continuously and automatically senses the amount of binder being delivered to the fibers at a fiber-forming station and, through the controller 178 and the valve 188 actuated thereby, effects a substantially constant rate of delivery of binder through a binder applicator 28 onto the newly attenuated fibers. By adjusting the controller 178 at each individual station, the amount of binder delivered onto the fibers at a station in a given unit of time may be adjusted so as to vary or regulate the amount of binder in various regions or zones of the mass of fibers collected on the conveyor flight 24.

This feature enables the fabrication of a mat from the collected mass of fibers wherein the binder at the boundary layers of fibers may have more or less binder than the core regions of the mat formed from the mass of fibers. Any excess or -waste binder filtering through the mass of fibers 26 and through the conveyor, and binder removed from the conveyor is delivered with the Wash water into the sump 50 and is pumped through the separator or filter 68 to filter out solids such as barium sulphate and stray fibers.

The recovered binder is recirculated through the tank 60 thence through the lines 76 and 84 with the wash water for cleaning the conveyor or to the binder mixing tank for reuse. Through this recirculating or reuse system, the Water loss or removal from .wash water circuit is limited to that adhering to the mass of fibers 26 and the moisture which is delivered from the vent stack to the blower 32 into the atmosphere or by normal evaporation. The removed Water is continuously replenished from the supply lines 54 and 55 to the binder system and through the line 58 into the tank 60, the extent of replenishment of fresh water being controlled by the level control mechanism 66 in the tank 60.

Binder filtering through the mass of fibers and the conveyor flight 24 is conducted to the sump 50 and recirculated to the binder mix tank whereby substantially all of the binder is eventually delivered onto fibers, avoiding the accumulation of otherwise waste binder in the sump 50 and tank 60.

The feed tank 150 is normally a standby tank but may be utilized in the event it is desired to change the composition of the binder mix without necessitating cleaning the feed tank 148. When the standby feed tank 150 is put into use, the valves 154, 157 and 17B are maintained in closed position by the programming means, the valve 170 opened, and the valves 154'and 157 brought into operation by the programming means to effect periodic delivery of successive binder batches into the standby feed tank 150 and their delivery to the pump 158.

It is found preferable to prepare successive batch of binder composition in intervals of a few minutes in order that the -binder does not become stale, and it isfound desirable to mix a fresh batch of binder at intervals of from ten to thirty minutes. The size of a batch and batch timing is dependent upon the quantities of fibers to be treated at the fiber forming stations and the amounts of binder delivered onto the fibers.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than as herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

We claim:

1. The method for continuously Washing a mineral fibercollecting foraminous conveyor, with Water and reusing said used Wash Water in the preparation of binder for application to the mineral fibers at a plurality of fiber-forming stations including the steps of feeding an alkaline detergent into the used wash water containing Waste binder to raise the pH to an alkaline level, dividing the detergenttreated Wash water into portions, Washing the conveyor with one portion of the detergent-treated wash Water to remove waste binder therefrom, directing another portion of the detergent-treated wash Water to a binder preparing station, mixing binder ingredients with the detergenttreated wash water at the binder preparing station, feeding an acidic neutralizing agent compatible with the binder into the wash Water for preparation of the binder to reduce the alkalinity to a pH f substantially 7, spraying the binder mix onto the fibers at the fiber-forming stations, and adding fresh Water to the used Wash Water sufficient in amount to maintain substantially constant the total volume of wash water.

2. The method for Washing a fiber-collecting conveyor for collecting mineral fibers at a plurality of fiber-forming stations to remove waste binder and reusing wash water in the preparation of binder for application to the fibers including the steps of feeding alkaline detergent into the wash water containing Waste binder to raise the pH to an alkaline level, heating the detergent-treated Wash Water to a temperature suflicientto substantially remove said Waste binder from the conveyor, dividing the heated wash Water into portions, conveying a portion of the heated Wash water to the region of the fiber-collecting conveyor and spraying the heated Wash Water onto the conveyor to remove Waste binder, cooling another portion of the heated Wash water to a temperature sufficient to be compatible with additional binder to be added thereto, conveying the cooled wash Water to a binder mixing station, feeding binder ingredients into the cooled wash Water to form a binder composition, feeding a neutralizing agent into the binder composition to decrease the pH factor to Substantially 7 to form a stable binder mix, conveying the binder mix to a region adjacent the fiber-forming stations, spraying the binder mix onto the fibers at each station, and adding fresh Water to the wash water to maintain substantially constant the volume of Wash Water.

3. The method according to claim 2 including the steps of continually sensing the pH factor of the wash water, and feeding the alkaline detergent into the Wash Water as determined bythe sensor to maintain substantially constant the pH factor of the wash water sprayed onto the conveyor to remove waste binder.

4. The method according to claim 2 including the steps of continually sensing the flow rate of binder mix at each fiber-forming station, and automatically regulating the flow rates to each fiber-forming station responsive to the sensor at each station to maintain substantially constant predetermined flow rates of binder sprayed onto the fibers at the respective fiber-forming stations.

5. Apparatus for processing attenuated mineral fibers at a plurality of fiber-forming stations where the fibers are continuously collected on a moving conveyor, nozzle means disposed adjacent the conveyor arranged to project wash water in engagement with the conveyor to remove waste binder adhering to the conveyor, a Wash water treating chamber, means for conveying the wash Water and Waste binder from the region of the conveyor into the Wash Water treating chamber, means for feeding alkaline detergent from a supply at a controlled rate into the chamber to raise the pH to an alkaline level, a receptacle to receive the wash Water and waste binder from the wash water treating chamber, heating means in the receptacle for heating the wash Water and binder, means for conveying a portion of the heated Wash Water and binder under pressure to the nozzle means, means for cooling another portion of the heated wash water and Waste binder, a tank for preparing binder mix, means for feeding binder ingredients into the tank, means for conveying the cooled wash water to the binder preparing tank, binder applicators adjacent the respective fiber-forming stations, and means for conveying binder mix from the binder preparing tank to the applicators at the fiber-forming stations to apply binder onto the fibers at each station.

6. The apparatus according to claim 5 including a binder flow sensing means at each fiber-forming station, each of said binder flow sensing means being operable to automatically regulate the flow of binder to the adjacent applicator `to maintain predetermined flow of binder to each applicator.

7. Apparatus for recovering Waste binder for -reuse on blast-attenuated mineral fibers produced at fiber-forming stations wherein the fibers are collected on a continuously moving foraminous conveyor including a recirculating wash Water system, a wash water receptacle adjacent the conveyor, a plurality of nozzles `disposed adjacent the conveyor, relatively movable brush means engaging the conveyor, means for feeding Wash water to the nozzles for engagement with the conveyor to remove waste binder adhering to the conveyor for collection in the wash water receptacle, means containing a supply of alkaline detergent, means for feeding the alkaline detergent from the supply at a controlled rate into the wash Water to maintain a substantially constant level of alkalinity, filter means, wash water heating means, pump means for` delivering Wash water` from the receptacle through the filter means and water heating means to the nozzles adjacent the conveyor, a binder mixing tank, a cooling tank, means arranged to feed some of the heated alkaline wash water to the cooling tank, means for feeding cooled Wash water from the cooling tank into the binder mixing tank, means for feeding binder ingredients including a neutralizing agent into the mixing tank whereby the agent reduces the alkalinity of the wash water and precipitates an insoluble salt, a circulating tank, a binder conveying manifold, binder applicators at the respective fiber-forming stations, said manifold connecting the circulating tank with the applicators, means for conveying successive batches of binder at periodic intervals into the circulating tank, and means continuously feeding the binder from the circulating tank through the manifold to the applicators for delivery onto the fibers at the several fiber-forming stations.

8. Apparatus for recovering waste binder for reuse on blast-attenuated mineral fibers produced at a plurality of 13 fiber-forming stations wherein the fibers are collected on a continuously moving foraminous conveyor including a closed wash water circuit, a wash water receptacle adjacent the conveyor, suction means for conveying away spent gases of the attenuating blasts, a washing chamber, means continuously delivering wash water to the chamber to recover waste binder entrained by the gases, a plurality of nozzles disposed adjacent the conveyor, relatively movable brush means engaging the conveyor, pumping means for feeding wash water to the nozzles and onto the conveyor to remove waste bindei adhering to the conveyor, means containing a supply of alkaline detergent, means for feeding the alkaline detergent from the supply at a controlled rate into the wash water to maintain a substantially constant predetermined level of yalkalinity of the wash water, filter means, wash water heating means, said pumping means moving the wash water through the filter means and heating means, a binder mixing tank, a cooling tank, means for diverting some of the heated alkaline wash Water to the cooling tank, means for feeding wash water from the cooling tank into the binder mixing tank, means for feeding binder ingredients including a neutralizing agent into the mixing tank whereby the agent reduces the alkalinity of the wash water and precipitates au insoluble salt, a circulating tank, Aa binder conveying manifold, binder applicators at the respective fiber-forming stations, said manifold connecting the circulating tank with the applicators, means for conveying successive batches of binder at periodic intervals into the circulating tank, and means continuously feeding the binder from the circulating tank through the manifold to the applicators for delivery onto the fibers at the several fiber-forming stations, and binder flow control means for automatically regulating ow of binder onto the fibers at each fiber-forming station.

References Cited UNITED STATES PATENTS 89,766 5/1869 Hofmann 162-274 2,707,690 5/ 1955 Pearson 65--3 2,732,296 1/ 1956 Simpson 162-275 X 3,021,563 2/1962 Slayter et al. 65-3 3,103,461 9/ 1963 Smith et al. 162--156 X S. LEON BASHORE, Primary Exwmner. 

1. THE METHOD FOR CONTINUOUSLY WASHING A MINERAL FIBERCOLLECTING FORAMINOUS CONVEYOR WITH WATER AND REUSING SAID USED WASH WATER IN THE PREPARATION OF BINDER FOR APPLICATION TO THE MINERAL FIBERS AT A PLURALITY OF FIBER-FORMING STATIONS INCLUDING THE STEPS OF FEEDING AN ALKALINE DETERGENT INTO THE USED WASH WATER CONTAINING WASTE BINDER TO RAISE THE PH TO AN ALKALINE LEVEL, DIVIDING THE DETERGENTTREATED WASH WATER INTO PORTIONS, WASHING THE CONVEYOR WITH ONE PORTION OF THE DETERGENT-TREATED WASH WATER TO REMOVE WASTE BINDER THEREFROM, DIRECTING ANOTHER PORTION OF THE DETERGENT-TREATED WASH WATER TO A BINDER PREPARING STATION, MIXING BINDER INGREDIENTS WITH THE DETERGENTTREATED WASH WATER AT THE BINDER PREPARING STATION, FEEDING AN ACIDIC NEUTRALIZING AGENT COMPATIBLE WITH THE BINDER INTO THE WASH WATER FOR PREPARATION OF THE BINDER TO REDUCE THE ALKALINITY TO A PH OF SUBSTANTIALLY 7, SPRAYING THE BINDER MIX ONTO THE FIBERS AT THE FIBER-FORMING STATIONS, AND ADDING FRESH WATER TO THE USED WASH WATER SUFFICIENT IN AMOUNT TO MAINTAIN SUBSTANTIALLY CONSTANT THE TOTAL VOLUME OF WASH WATER.
 5. APPARATUS FOR PROCESSING ATTENUATED MINERAL FIBERS AT A PLURALITY OF FIBER-FORMING STATIONS WHERE THE FIBERS ARE CONTINUOUSLY COLLECTED ON A MOVING CONVEYOR, NOZZLE MEANS DISPOSED ADJACENT THE CONVEYOR ARRANGED TO PROJECT WASH WATER IN ENGAGEMENT WITH THE CONVEYOR TO REMOVE WASTE BINDER ADHERING TO THE CONVEYOR, A WASH WATER TREATING CHAMBER, MEANS FOR CONVEYING THE WASH WATER AND WASTE BINDER FROM THE REGION OF THE CONVEYOR INTO THE WASH WATER TREATING CHAMBER, MEANS FOR FEEDING ALKALINE DETERGENT FROM A SUPPLY AT A CONTROLLED RATE INTO THE CHAMBER TO RAISE THE PH TO AN ALKALINE LEVEL, A RECEPTACLE TO RECEIVE THE WASH WATER AND WASTE BINDER, MEANS FOR CONVEYING A PORTION OF THE HEATED WASH WATER AND BINDER UNDER PRESSURE TO THE NOZZLE MEANS, MEANS FOR COOLING ANOTHER PORTION OF THE HEATED WASH WATER AND WASTE BINDER, A TANK FOR PREPARING BINDER MIX, MEANS FOR FEEDING BINDER INGREDIENTS INTO THE TANK, MEANS FOR CONVEYING THE COOLED WASH WATER TO THE BINDER PREPARING TANK, BINDER APPLICATORS ADJACENT THE RESPECTIVE FIBER-FORMING STATIONS, AND MEANS FOR CONVEYING BINDER MIX FROM THE BINDER PREPARING TANK TO THE APPLICATORS AT THE FIBER-FORMING STATIONS TO APPLY BINDER ONTO THE FIBERS AT EACH STATION. 